کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5363931 1388308 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of CeO2-ZrO2 present in Pd/Al2O3 catalysts on the redox behavior of PdOx and their combustion activity
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Effects of CeO2-ZrO2 present in Pd/Al2O3 catalysts on the redox behavior of PdOx and their combustion activity
چکیده انگلیسی
The ceria-zirconium-modified alumina-supported palladium catalysts are prepared using impregnation method with H2PdCl4 as Pd source, hydrazine hydrate as reducing agent. The physicochemical properties of these catalysts are characterized by BET surface area (BET), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), temperature programmed reduction (H2-TPR) and temperature programmed oxidation (O2-TPO) techniques, and their catalytic activities for the combustion of methane are examined. The results show that the palladium mainly exist in a highly dispersed PdO species on Ce-Zr-rich grains as well as Al2O3-rich grains surfaces, and a stable PdO species due to the strong interaction between PdO and CeO2-ZrO2 on the Ce-Zr/Al2O3 surfaces. The catalytic activity is strongly related to the redox behavior of PdO species highly dispersed on Ce-Zr-rich grains and Al2O3-rich grains surfaces, and the higher the reducibility of the PdO species, the higher the catalytic activity. The presence of Ce-Zr in Pd/Al2O3 catalyst would inhibit the site growth of PdOx particles and decomposition of PdO to Pd0, and the reoxidation property of Pd0 to PdOx is significantly improved, which obviously increases thermal stability and catalytic activity of Pd/Ce-Zr/Al2O3 catalyst for the methane combustion.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 254, Issue 15, 30 May 2008, Pages 4701-4707
نویسندگان
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